Spring threading-die



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SPRING THREADING DIE.

APPLICATION FILED APR.22| I9I6.

atent Aug. 15, 1916.

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VALENTINE OLB, OF BRIDGEPOIRT, CONNECTICUT.

SPRING THREADINGr-DIE.

Application filed April 22, 1916.

To all 'whom t may concern:

Be it known that I, VALENTINE ULB, a citizen of the United States, residing at Bridgeport, county of Fairfield, State of Connecticut, have invented an Improvement in Spring Threading-Dies, of which the following is a specification.

This invention relates to the class of thread cutting dies which may be defined as round split dies of the solid type; that is, dies formed integral from a solid block of steel and split upon one side to permit expansion and contraction of the cutting edges to provide for variation in sizes of pipes and rods and to enable the operator to cut as light or deep a thread as may be required. It has been a serious objection to this class of dies as heretofore constructed that they were extremely liable to break on the opposite side from the split. In order to wholly overcome this objection and provide a solid split die that may be used and sharpened until worn out, and which may be expanded and contracted, as may be required, Without danger of breakage, I have devised the novel spring die which I will now describe, referring to the accompanying drawing forming a part of this specification, and using reference characters to indicate the several parts.

Figure 1 is an elevation of my novel die; Fig. 2 a plan view thereof; and Fig. 3 a section on the line 33 in Fig. 2, looking in the direction of the arrows.

10 denotes the body of the die which is provided with a central opening 11, cutting edges 12, clearance spaces 13 between the cutting edges7 and a split 14: leading from one of the clearance spaces through to the periphery of the body. These features arev all common in this class of die. The essential feature of novelty in the present die is that the two halves of the body are connected by a spring neck 15 lying directly opposite to the split. The inner wall of this neck is the wall of the clearance space opposite opies of this patent may be obtained for five cents each, by addressing the Speccation of Letters Patent.

Patented Aug. 15, 1916. Serial No. 92,826.

to the split. In order to give to the neck a substantially uniform transverse thickness, metal is removed from the outer side of the body its entire thickness, leaving rounded grooves 16 lying parallel with the axis of the body on opposite sides of a diametric line extending through the split. The exact length of the neck or the shape or location of the grooves or whether or not all portions of the neck are of exactly uniform transverse thickness are unimportant so far as the principle of the invention is concerned. I have shown the deepest portions of the grooves as approximately on radial lines extending through the mid-length of contigu-l ous cutting edges. This, however, is unimportant, as the neck may be made longer or shorter, if preferred. I End the proportions illustrated entirely satisfactory in use. The essential feature, however, is to give to the neck suflicient length so that the spring action in expanding and contracting the die will not be confined to a point directly opposite the split, but will be taken up by a neck of sufficient length to practically eliminate danger' of breakage. Depressions 17 are provided in the periphery of the die for engagement by set screws in adjusting the die and in securing it in place.

I-Iaving thus described my invention, I claim:

A die of the character described comprising a body having cutting edges, clearance spaces, a split extending from one of the clearance spaces through the wall of the body, and opposite to the split a curved neck connecting the halves of the body, the inner face of said neck being the wall of one of the clearance spaces and the outer face being formed by removing metal from the outer side of the body on opposite sides of a diametric line extending through the split.

In testimony whereof I aflix my signature.

VALENTINE OLB.

lCommissioner of Patents,

Washington, D. C. 

